Saponin对不同趋化因子受体的活化的影响研究

本文通过在稳定表达趋化因子受体的细胞系CHO/CXCR1、CHO/CXCR2、CHO/CXCR3、CHO/CXCR4和CHO/CCR5上进行[35S]GTPγS结合实验，研究了Saponin 对不同趋化因子受体活化的影响。实验结果表明：① 对于CHO/CXCR1和CHO/CXCR4， 在反应体系中添加10 μg/ml Saponin能提高受体G蛋白与[35S]GTPγS的特异性结合，使刺激比率(CPMAgonist/CPMBasal)分别从125%和184%扩大到481%和415%；② 对于CHO/CCR5，10 μg/ml Saponin对受体G蛋白与[35S]GTPγS的特异性结合无影响，刺激比率大小未变；③ 对于CHO/CXCR2和CHO/CXCR3，10 μg/ml Saponin降低了受体G蛋白与[35S]GTPγS的特异性结合，使刺激比率分别从171%和168%减小到130%和114%。实验结果表明Saponin是与受体发生作用，对于不同的趋化因子受体，Saponin对受体的活化的影响不同。

Effect of Saponin upon the Activation of Different Chemokine Receptors

The effect of Saponin upon the activation of various chemokine receptors was studied by [35S]GTPγS binding assay on cell lines of CHO/CXCR1, CHO/CXCR2, CHO/CXCR3, CHO/CXCR4 and CHO/CCR5 which stably expressed chemokine receptor CXCR1, CXCR2, CXCR3, CXCR4, and CCR5, respectively. The results indicated that: ① On CHO/CXCR1 and CHO/CXCR4, the addition of 10 μg/ml of Saponin to the assay system could facilitate the activation of the receptor and the specific binding of [35S]GTPγS to receptor G-protein complexes, enlarge the stimulation ratio (CPMAgonist/CPMBasal) of [35S]GTPγS binding assay from 125% and 184% to 481% and 415%, respectively; ② On CHO/CCR5, 10 μg/ml of Saponin had no effect on the activation of the receptor, the specific binding of [35S]GTPγS to receptor G-protein and the stimulation ratio; ③ On CHO/CXCR2 and CHO/CXCR3, 10 μg/ml of Saponin inhibited the activation of the receptor and reduced the stimulation ratio from 171% and 168% to 130% and 114% respectively. It was revealed that Saponin had something to do with receptors but not G-protein. And it was concluded that the effect of Saponin upon the activation of various chemokine receptors were different.